(Sharecast News) - Share Plc, formerly The Share Centre, confirmed on Friday that it has received a preliminary approach from online investment platform Interactive Investor, which may or may not lead to an offer being made for the company."There can be no certainty that an offer will be made for the Company, nor as to the terms on which an offer may be made," it said in a statement.Under takeover rules, Interactive Investor now has until 1700 BST on 31 May to either announce a firm intention to make an offer for Share or walk away.At 1115 BST, the shares were up 22% at 37.20p.